code: def is_vertex(ent):
      """If the input entity is a vertex return True.
  
      Parameter
      =========
  
      ent :
          Denotes a geometric entity representing a point.
  
      Examples
      ========
  
      >>> from sympy import Point
      >>> from sympy.integrals.intpoly import is_vertex
      >>> is_vertex((2, 3))
      True
      >>> is_vertex((2, 3, 6))
      True
      >>> is_vertex(Point(2, 3))
      True
      """
      if isinstance(ent, tuple):
          if len(ent) in [2, 3]:
              return True
      elif isinstance(ent, Point):
          return True
      return False
  
imports: from functools import cmp_to_key
  from sympy.abc import x, y, z
  from sympy.core import S, diff, Expr, Symbol
  from sympy.core.sympify import _sympify
  from sympy.geometry import Segment2D, Polygon, Point, Point2D
  from sympy.polys.polytools import LC, gcd_list, degree_list, Poly
  from sympy.simplify.simplify import nsimplify
label_desc: Use image node_id 21 for calling a global function with example usage: is_vertex(ent) and returns: False, True, True